Abstract Details

Design: Retrospective, uncontrolled case series.
Serial corneal Scheimpflug tomography and subjective refractions were used to confirm pre-operative ectasia progression, defined by one or more of the following: >1.5 dioptre (D) increase in Kmax; >1.5D increase in anterior K2; >0.5D increase in posterior K2; >1D increase in refractive astigmatism; >1 line loss of corrected distance visual acuity (CDVA), > 13µm decrease in central or thinnest pachymetry. Patients with active ocular surface disease and those with a minimum corneal thickness <375 µm were excluded.
Following manual epithelial debridement, the cornea was soaked in riboflavin 0.1% in HPMC for either 20 minutes (if minimum pachymetry ≥400µm) or 10 minutes (if minimum pachymetry <400µm). Continuous UVA exposure at 30mW/cm2 for 4 minutes was used in all eyes (total energy 7.2mJ/cm2). The primary outcome measure was the change in Kmax at 12 months. Treatment failure was defined by an increased in Kmax of >1.5D at 12 months.

Results:

Rapid CXL was performed on 33 eyes of 30 patients (32 keratoconus, 1 post-LASIK ectasia; mean age 27 years). At 12 months, the mean (± standard deviation) change in Kmax was -0.45 ± 2.36D (p=0.29). 4 (12%) of 33 eyes were still progressing, with a mean increase in Kmax of 2.7 ± 1.1D. Manifest cylinder remained unchanged (mean -0.1 ± 2.7D, p=0.88). One (3%) eye lost more than 2 lines of CDVA. One (3%) sterile infiltrate developed which responded rapidly to additional topical steroids. No infective complications occurred.